Melissa
I've only got one of your videos working (the 5th of Feb one) - I don't know why the others won't play. But if I can make 2 small suggestions:
1 I would really recommend using your ring finger for the bottom bass button at this early stage. Of course there are plenty of better players than me who play this way, but I have found having at least 3 active fingers on the left hand useful. You may have to hold your hand slightly differently - with more of the whole hand going through the strap to get the reach right, but I'd be keen to do that.
2 Try not having such a big top / bottom swing out of the bellows. You drop the bellows towards the floor on the pull, and then reverse that on the push - lifting the end plate towards the ceiling (of course I'm exaggerating). I think these are habits which make things further down the line harder, so why not develop good habits now.
I think the box sounds good, by the way.
You could also even now experiment with short chord notes as an extra exercise. I notice that you said the hands want to mimic each other, rather than be independent, but I don't think it matters if the right hand is also short at the same time for the moment.
Good luck, progress indeed.